VW Mastercars Claremont- Bad service

At 21st of December 2019 I was looking at the option to trade in my VW Polo on a T-Cross. But mentioned that I would like to wait till January. The salesman then persuaded me to close the deal immediately as : 1- Prices will go up 1 January 2- I will enjoy an installment break till March 2020 ( NOT TRUE on my contract it states 31 January, and the lady working with finance told me a **** and bull story about that is the only way to negotiate a decent interest rate) 3- I will not have to pay another installment end December on the Polo I traded in. All sounded good, and then they took ownership of the Polo 27 December. And to my surprise 31 December the installment goes off. I immediately contacted the salesman who first responded that the installment was art of the buyout, which was a lie, and when I reminded him that i had a witness to the deal that was discussed, it was agreed that i must send my statement where the money was deducted, and they will refund me. After several emails , I waa then promised the payment as made and I will receive a POP. Three days later, and two emails asking for the POP, I still did not get my money or the POP. I even copied in the financial Director. And still no response, or POP. I hate being **** to to close a deal...... Last time ever I will support VW as a brand.